<template>
  <div>
    <h1>当前和为:{{this.sum}}</h1>
    <select v-model.number="n">
      <option value="1">1</option>
      <option value="2">2</option>
      <option value="3">3</option>
    </select>

    <button @click="increment">+</button>
    <button @click="decrement">-</button>
    <button @click="incrementOdd">当前求和为奇数再加</button>
    <button @click="incrementWait">等等再加</button>
  </div>
</template>

<script>
  export default {
      name: "Count",
      data(){
        return{
          sum:0, //当前的和
          n:1, //用户选择的数字
        }
      },
    methods:{
      increment(){
          this.sum += this.n
      },
      decrement(){
        this.sum -= this.n
      },
      incrementOdd(){
        if(this.sum %2 !== 0){
          this.sum += this.n
        }
      },
      incrementWait(){

      }
    }

    }

</script>

<style scoped>
  button{
    margin-left:5px;
  }

</style>